regenerate all html pages on upgrade
when we upgrade debci, several HTML pages are only regenerated when there is new data. instead, all pages should be refreshed right away.
this includes two things:
- adding an option to both debci-generate-index and debci-generate-html for forcing regenerating both json files and pages for all packages on all suites and all architectures.
debci generate-indexwith such option on upgrades (maybe from debci-migrate, which is already called on upgrades)